Writing instrument



Oct. 29, 1968 K, oss 3,408,148

WRITING INSTRUMENT Filed Aug. 1, 1966 2 Sheets-Sheet 1 mvzu'ron HeLmwl: Karl. 3v095 3 flpwwc I; 480% Get. 29, 1968 K, BROSS 3,408,148

WRITING INSTRUMENT Filed Aug. 1, 1966 2 Sheets-Sheet 2 mvzn'ron HeLmwk KqyL 3voss 3 rwwe 2 H Qttovmgs United Patent 01 iice Patented Oct. 29, 1968 3,408,148 WRITING INSTRUMENT Helmut Karl Bross, Weichselgarlenstrasse Altenberg, near Nuremberg, Germany Filed Aug. 1, 1966, Ser. No. 569,427 Claims priority, application Germany, Aug. 2, 1965, B 8 106 11 Claims (Cl. 401-113) ABSTRACT OF THE DISCLOSURE A retractable writing instrument including a writing element movable in a casing and a control mechanism for controlling the position and movement of the element in accordance with the relationship between a cam and a plurality of guide edges at least some of which are defined by slots formed in the casing and separated from one another and which are positioned to control forward and retracted stop positions for the cam and to determine the path of cam movement in both directions between such stop positions.

struments is in its retracted position, it is laterally covered by the casing, while in its forward position, it projects from the casing. The mechanism may be operated by exerting a pressure upon an actuating member, for example, a pushbutton or pressure cap, on the rear end of the instrument which is movable in the axial direction either in or on the casing. The forward movement of this actuating member occurs against the action of a compression spring and its retracting movement occurs by the action of this spring which is generally supported on a shoulder of the writing element.

It is an object of the present invention to improve such a writing instrument by providing it with a control mechanism which comprises two operating members which are movable relative to each other in the axial direction of the instrument and one of which constitutes the casing for the instrument surrounding the writing element and having a front opening at one end through which the element moves, and the other operating member including an actuating member at the other end of the casing, the actuating member having an actuating end and being operatively associated with the writing element for acting thereupon when the actuating member is depressed and a spring opposing the depression movement of the actuating member and writing element for urging the writing element into its retracted position. One of these operating members is providedwith at least one control cam which is movable in a radial direction relative to the longitudinal axis of the instrument and may be pressed by a resilient force against the other operating member. When the actuating member is moved, this control cam will slide along guide edges which are provided on the other operating member, and it will thereby be moved to end positions in which it will be arrested when the writing element is in the advanced or retracted positions.

The angular displacement of the sections of the different guide edges relative to each other constitutes an essential feature of the invention which is necessary for avoiding improper functions of the mechanism. In this connection it is important that the largest possible forward movement of the actuating member from its retracted position is larger than the distance between the arresting positions. The arresting position will not be reached until under the action of the spring the actuating member or the cam has again been moved back for a short distance from its farthest possible advanced position. The guide edges according to the invention may be provided by step-shaped projections or recesses, by slotshaped apertures, or by grooves on one of the two operat ing members. Since the operating member which is provided with the guide edges is usually made of plastic by injection molding, it should be designed so as to be easily removed from the mold. This may be easily attained because of the particular arrangement of the guide edges in accordance with the invention. The movement of the control cam in the peripheral direction may cause the actuating member to be likewise turned. If such a turning of the actuating member is undesirable, provisions have to be made to insure that the control cam will move in the peripheral direction independently of the actuating member. This may be attained, for example, by providing the control cam on an arm which is secured to the actuating member and adapted to be bent not only in the radial direction, but also in the peripheral direction.

It the actuating member is also to be turned, it is necessary that the control cam and the arm which might carry the same will oppose a peripherally directed force with such a resistance that the actuating member will be taken along in the peripheral direction by the movement of the control cam. In this case, the arm carrying the control cam should therefore be incapable of bending in the peripheral direction.

Even though when employing an actuating member in the form of a pushbutton, the guide edges are generally provided on the inner side of the casing of the writing instrument or, when employing a pressure cap, they are provided on the outer side of the casing, it is in principle also possible to provide the guide edges on the actuating member. The control cam and the arm on which the cam might be mounted would in such a case be provided on the casing of the writing instrument.

When speaking of the casing of the writing instrument and of the actuating member in connection with the present invention, these terms are also meant to include any possible extensions or projections of these operating members on which the control elements according to the invention may be provided.

The improvements according to the invention consist primarily in designing the different parts of the mechanism, which are usually made of plastic and produced by injection molding, so as to be of a very simple shape, to permit them to be easily and quickly assembled, to opcrate properly at all times even though the extent of their relative movement is relatively small, and to be wearresistant so that the writing instrument will be fully operative for a very long time.

The features and advantages of the present invention will become more clearly apparent from the following detailed description which is to be read with reference to the accompanying drawings, in which FIGURE 1 shows, partly in section, a side view of a ball-point pen according to the invention, in which the actuating member is in its retracted position;

FIGURE 2 shows an enlarged side view of the part of the casing of the ball-point pen according to FIGURE 1 which constitutes the most important feature of the invention;

FIGURE 3 shows a cross section which is taken along the line III-III of FIGURE 2;

FIGURE 4 shows a perspective View of the actuating member;

FIGURE shows a side view of the actuating member;

FIGURE 6 shows an enlarged side view of a part of the casing of a writing instrument according to a modification of the invention;

FIGURE 7 shows a cross section which is taken along the line VII-VII of FIGURE 6;

FIGURE 8 shows an enlarged side view of a part of the casing of a writing instrument according to a further modification of the invention;

FIGURE 9 shows a longitudinal section of the rear part of a two-part casing of a writing instrument accord ing to still another modification of the invention; while FIGURE shows a perspective view of the cam of the writing instrument according to FIGURE 9.

In the drawings, in which all functionally similar parts are designated by the same reference numerals, the writing instrument according to the invention comprises a casing 1 in which a pushbutton 2, which projects from the rear end of the casing, and a writing element 3, for example, in the form of a ball-point insert or refill are slidable in the axial direction. When the upper end of the pushbutton 2 is depressed, it will act upon the writing element 3 so as to shift the same from its retracted position within the casing against the action of a compression spring 4 to its writing position in which the writing tip 3' projects from the front end of easing 1. Spring 4 acts at one end upon a shoulder 1 on the inner wall of the casing and at its other end upon a flange 3 on the refill 3. As illustrated particularly in FIGURES 4 and 5, the part of the pushbutton 2 which is at all times located within the casing 1 is provided with an arm 5 which may be integral with the pushbutton.

The free end of arm 5 is provided with a control cam 6 which projects toward the wall of casing 1 and has on its upper side two Work surfaces 6' and 6" which are inclined toward the sides of the cam and are tapered toward each other and are operatively associated with the two upper guide edges of the other operating member, as shown in FIGURES 2 and 6, which are inclined in opposite directions. The work surfaces 6' and 6" are further inwardly inclined from the outer edge of the cam which is adjacent to the casing. The lower side of the cam is provided with at least one further work surface 6" which is adapted to cooperate with the lowest guide edge 9 and extends like the work surfaces 6' and 6" from the upper outer side downwardly to the inner side and may have an inclination corresponding to that of the guide edge 9. The shape of cam 6 is illustrated particularly in FIG- URES 4 and 5. If the guide edges are designed so that, when the mechanism is operated, the lower side of cam 6 will be pressed against the upper guide edge 7 (FIGURE 8), the lower side of the cam may -be provided with an additional work surface which is inclined to the work surface 6".

According to the embodiments of the invention as illustrated in FIGURES 1 to 8, the two uppermost guide edges 7 and 8 for the control cam 6 are formed by slotshaped apertures which are provided in the wall of the casing. The lowest guide edge 9 of the embodiments according to FIGURES 1 to 7 is located on a web-shaped projection 10 on the inner Wall of the casing, but it may also be provided like the two other guide edges on a slotshaped aperture in the wall of the casing (FIGURE 8).

At least one group of three guide edges 7, 8, and 9 are disposed above each other and are inclined relative to the vertical longitudinal axis of the writing instrument, and the inclinations of the two lowest guide edges extend in opposite directions to each other. According to the embodiments of the invention as shown in FlGURES l to 7 and FIGURE 9, the inclination of the uppermost guide edge 7 is also opposed to the inclination of the or intermediate guide edge 8, while according to the cinbodiment as shown in FIGURE 8 the inclination of the uppermost guide edge extends in the same direction as the inclination of the central guide edge 8. While according to the first-mentioned embodiments the upper side of cam 6 cooperates with the uppermost guide edge 7, the last-mentioned embodiment provides that, when the mechanism is actuated, the lower side of the cam will be pressed against the uppermost guide edge 7. Those guide edges which cooperate with the upper side of the cam are provided with an inclined surface which is designated in the drawings by the numerals 7' and 8' and corresponds to the work surfaces 6' and 7. The inclination of the guide edges and the work surfaces 6' and 7 of the cam insures that these surfaces will properly engage with the guide edges so that improper functions of the mechanism will be avoided.

FIGURES 2, 6,, 8, and 9 also illustrate the angularly offset relation of the guide edges or sectionsthereof relative to each other, as above described.

The control mechanism as illustrated in FIGURE 2 is designed so as to permit the actuating member 2 to be turned when the mechanism is actuated. Arm 5 is for this purpose designed so as to be very rigid in the peripheral direction so as not to yield under a force acting in the peripheral direction upon the cam. Arm 5 is therefore adapted to bend only in the radial direction. According to the other embodiments of the invention in which the actuating member should not turn during the actuation of the mechanism, cam 6 must be movable independently in the peripheral direction relative to the actuating member which requires the arm to be bendable in the peripheral direction.

The principles of the function of the control mechanism according to the invention will be hereafter described with reference to FIGURE 2, in which the control cam 6 is located in the arrested position which corresponds to the retracted position of the actuating member and the refill 3. This position is determined by the stop corner 12 which is provided on the end of the guide edge 7 which is nearest to the actuating surface 2' of the pushbutton. If the pushbutton 2 is depressed, earn 6 will engage with its inclined surface 6" upon the edge of the slot-shaped aperture which is directly opposite to the guide edge 7. The edge portion 13 upon which the cam engages is preferably designed so that it will not be affected by a force which tends to press the cam toward the remote end of the guide edge 7. This edge portion is therefore designed so as to extend at a right angle to the longitudinal axis of the casing. The cam is thus pressed inwardly whereby a substantially resilient force is produced in the radially bendable arm 5. When the pushbutton 2 is further depressed, this force causes the cam 6 to engage in front of the section of guide edge 8 which lies axially underneath the stop corner 12. If the pushbutton is then released, cam 6 will slide during its return movement under the action of spring 4 along the guide edge 8 into the stop corner 14 which is provided at the end of guide edge 8 which is closest to the actuating surface 2 of the pushbutton. During this movement, pushbutton 2 has also turned to a certain extent in the clockwise direction. The stop corner 14 arrests the pushbutton 2 and thus also the refill 3 in their forward position. It is, however, also possible during the forward movement of the pushbutton from its retracted position and the corresponding movement of cam 6 in a direction substantially parallel to the axis of the casing, to move the cam beyond the guide edge 7 to the farthest possible forward position. It is then important that the cam will not pass into the range of guide edge 9 so as to insure that, when the pushbutton 2 is released and moves toward the rear, the cam will move into the area of guide edge 8 and thus also pass into the stop corner 14. When the pushbutton is again depressed, cam 6 will emerge from the stop corner 14 because of its engagement upon the edge 15 which extends at a right angle to the axis of the casing, and in its farthest forward position it will finally engage with the lowest guide edge 9 which is located axially underneath the stop corner 14, and will then slide along this guide edge because of the pressure which is exerted upon the pushbutton. Pushbutton 2 is thereby further turned until cam 6 is located axially underneath a section of the upper guide edge 7 which is angularly offset relatively to the stop corner 14. If the pushbutton is then released, cam 6 will move under the action of spring 4 toward the guide edge 7. As soon as it engages upon this edge, it will be returned to its initial position, that is, into the stop corner 12, whereby pushbutton 2 will be turned back in the counterclockwise direction to its initial position. In order to allow the pushbutton to turn freely during its movement from the forward stop position to the farthest possible forward position, it is advisable to make the actuating surface 2' of the pushbutton of a spherical shape so that only a very low friction will occur between this surface and the finger depressing the same. The path of movement of the control cam 6 is indicated in FIGURE 2 by the arrows on the dot-and-dash line.

It is obvious that the slot-shaped apertures forming the guide edges may also be replaced by corresponding grooves which are provided in the wall of the respective operating member.

In the other embodiment of the invention the control mechanism is designed so as to prevent the pushbutton from turning'when the mechanism is actuated. In the embodiments according to FIGURES 6 and 7, casing 1 has for this purpose a square cross section in accordance with the square cross section of the pushbutton 2. Of course, even though the casing might have a circular cross section, it is possible to prevent a rotation of the pushbutton also by other conventional means. In order to permit the control cam 6 to move in the peripheral direction despite the fact that the pushbutton is nonrotatable, the arm 5 must be capable of bending in the peripheral direction. In order to prevent any improper operation of the mechanism due to the spring force which is produced in arm 5 by thus being bent, the inner side of the casing is provided with guide edges 16 and.17 which extend in the axial direction of the casing. Cam 6 on arm 5 will slide along these guide edges 16 and 17 when during the actuation of pushbutton 2 cam 6 is moved along a line extending substantially parallel to the axis of the casing from the upper guide edge 7 to the guide edge 8 "or, after leaving the guide edge 9, to the guide 7. Guide edges 16 and 17 which in the embodiment according to FIGURES 6 and 7 are formed by grooves 18 and 19 in the inner wall of the casing prevent the arm 5 from swinging back to its socalled neutral position (i.e. the position in which the arm is not acted upon by a resilient force in the peripheral direction). According to FIGURE 6, arm 5 has reached its neutral position shortly before cam 6 enters into the stop corner 14. Of course, arm 5 may, however, also be mounted on pushbutton 2 so that its neutral position will be attained in any other position of cam 6,

for example, in the stop corner 12. In any event, however,

the guide edges 18 and 19 which extend parallel to the axis of the casing are to 'be arranged so as to prevent the arm'5 from swinging laterally to any undesired extent. In FIGURE 6, the edge portions 13 and 15 are designed so as to have an inclination in a direction opposite to the inclination of the guide edges 7 and 8, respectively.

This prevents the arm 5 from swinging back to its neutral position at the moment when cam 6 emerges from the stop corners 12 and 14.

FIGURE 8 illustrates a further embodiment of the invention. When this mechanism is actuated, cam 5 will move from the stop corner 12 in the direction as indicated by the arrows on the dot-and-dash line, that is, opposite to the direction in which it is moved in the em- 6 bodiments according to FIGURES 2 and 5. After leaving the guide edge 7, cam 6 will engage at the remote end of this edge into the forward guide groove 16 which extends parallel to the axis of the casing and the depth of which may increase in the direction toward the guide edge 8. Cam 6' then passes through'the two consecutive slot-shaped apertures on which the guide edge 8 is provided which cooperates with the work surface 6' and with the guide edge 9 which cooperates with the work surface 6" of the cam. If the pushbutton is released when it is fully depressed, cam 6 will engage into the return guide groove 17 which likewise extends parallel to the axis of the casing and the depth of which may decrease in the direction toward the guide edge 7. In order to facilitate the passage of the cam into the return guide'groove 17, it may be advisable to provide special means, for example, in the form of a projection 20 which is provided on the inner side of the casing underneath the remote end of the lower guide edge 9 and has an inclined surface 21 upon which the arm 5 engages when it moves in the direction toward the remote end of guide edge 9, whereby the arm is pressed slightly inwardly. When the arm moves upwardly with the pushbutton, the projection 20 will no longer be effective and the cam may therefore snap behind the uppermost guide edge 7.

In the further'embodiment of the invention as illustrated in FIGURE 9, the guide edges 7, 8, and 9 are formed by offsetting certain surface parts 22, 23, 24, 25, and 26 of the inner side of the casing relative to each other in the form of steps. As seen from the longitudinal axis of easing 1, surface 23 lies farther outside than surface 22 so that the uppermost guide edge 7 is formed by the step between these two surfaces. Surface 24 again lies farther outside than surface 23 so that the central guide edge 8 is formed by the step between these surfaces. Between surface 24 and the surface 25 which lies farther outside than the latter, the inner side of easing 1 is provided with a ledge 10 which extends parallel to the axis of the casing and the upper end of which forms the lowest guide edge 9. The upper end of surface25 is provided with the stop corner 14 for arresting the cam 6 in its forward position. Adjacent to the stop corner 14 a groove 32 extends to the rear end of casing 1. This groove 32 is provided for facilitating the removal of the casing from the mold and should, of course, have a narrower Width than cam 6. Surface 26 is located farther outside than surface 25 so that a guide edge 17 is formed which extends parallel to the axis of the casing and along which cam 6 or a nose 27 thereon may slide when the cam engages against the guide edge 9 and is then pressed toward the surface 26. Nose 27 then snapsin adjacent to the edge 17. Within the path of travel of the cam which is indicated in FIGURE 9 by the arrows on the dot-anddash line, an inclined surface 26' is provided which extends from the surface 26 to the surface 23 and permits the cam 6 to slide along the same so as to be lifted to the level of the surface 23. In order to prevent the nose 27 on cam 6 from being caught in groove 32 during its movement to the stop corner 12, a bevel 28 is provided at the point of transfer from this groove to the part of surface 23 at the right side thereof in FIGURE 9. The control mechanism according to FIGURE 8 may be employed especially if the casing consists of two parts. The actuating member or pushbutton may then be easily inserted into the rear part of the casing from the front opening thereof.

In order to facilitate the assembly of the control mechanism, several groups and the guide edges as above described may be provided on the inner Wall of the casing.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

' 1. In a writing instrument having a front end and a rear end and provided with at least one writing element slidable in the direction of the axis of said instrument, and a control mechanism associated with said writing element for moving it forwardly in one direction into a forward position and for retracting it in the opposite direction into a retracted position in said instrument and for arresting said writing element in the forward position or in the retracted position, said mechanism being composed of two operating members movable relative to each other in the axial direction of the said instrument, one of said operating members constituting a casing for said instrument surrounding said element and having at said front end of said instrument a front opening through which said element moves, and the other said operating member including an actuating member at the other end of said casing, said actuating member having an actuating end and being operatively associated with said writing element for acting thereupon when said actuating member is depressed, and a spring opposing the depression movement of said actuating member and said writing element for urging said writing element into said retracted position, one of said operating members being provided with at least one control cam which is movable in the radial direction relative to the longitudinal axis of said instrument and which is arranged to be pressed, under the action of a substantially resilient force, against the other one of said operating members, said other one of said operating members including means defining guide edges along which said cam is movable when said actuating member is moved, said cam then moving to, and being arrested in, respective stop positions when said writing element is moved to its forward or retracted positions, respectively, the improvement wherein: at least one group of three guide edges is provided which are disposed one above the other along the longitudinal axis of said instrument to present an uppermost guide edge, an intermediate guide edge, and a lowest guide edge, said uppermost guide edge being furthest from said front opening and all of said guide edges being inclined relative to the vertical longitudinal axis of said writing instrument, each of said guide edges having a near end and a remote end with reference to said actuating end of said actuating member; the lowermost two of said guide edges are inclined in opposite directions with respect to each other; at said near end of said uppermost guide edge a stop corner is provided for arresting said control cam in said retracted position of said Writing element; at said near end of said intermediate guide edge a stop corner is provided for arresting said control cam in said forward position of said writing element; said intermediate guide edge is provided with a section which is located in line with said uppermost guide edge, as seen in the axial direction of the instrument; said lowest guide edge is provided with a section which is located in line with said stop corner of said intermediate guide edge, as seen in the axial direction of said instrument; said near end of said lowest guide edge is angularly offset relative to said remote end of said intermediate guide edge, as seen in the axial direction of said instrument; said near end of said lowest guide edge is angularly offset relative to said remote end of said intermediate guide edge in the direction of its inclination; said lowest guide edge is provided with a section which is angularly offset relative to said stop corner of said intermediate guide edge and is located axially in line with a section of said uppermost guide edge which is also angularly offset relative to said stop corner of said intermediate guide edge; such angular displacements are dimensioned such that, when said actuating member. is moved forwardly from its retracted position, the path of cam movement extending beyond said intermediate guide edge lies outside of the effective range of said lowest guide edge and the path of cam movement from said lowest to said uppermost guide edges lies outside of the effective range of said intermediate guide edge; and said cam has upper and lower sides provided with work surfaces which are operatively associated with said guide edges.

2. A writing instrument as defined in claim 1, wherein the inclination of said intermediate guide edge extends in the opposite direction to the inclination of said uppermost guide edge.

3. A writing instrument as defined in claim 1 wherein said guide edges are provided on slot-shaped apertures.

4. A writing instrument as defined in claim 1 wherein the edge portions opposite said stop corners of said guide edges extend at right angles to the longitudinal axis of said casing.

5. A writing instrument as defined in claim 3, wherein the edge portions opposite to said stop corners of said guide edges are inclined in the opposite direction to the inclination of said guide edges.

6. A writing instrument as defined in claim 2, wherein said operating member provided with said guide edges is tubular and said guide edges are provided as intermediate surface parts of the inner side of said" tubular operating member and are spaced at different distances from the axis of said casing. I

7. A writing instrument as defined in claim 6, wherein the distances of said surface parts from the axis of said casing increase in the direction of movement of said cam from its rear stop position, which corresponds to the retracted position of said writing element, and along the path of movement of said cam from that surface part which is most remote from said actuating end of said actuating member to that surface part which is nearer said actuating end, and on which said cam moves to said rear stop position, an inclined surface is provided which permits said cam to slide to said surface part which is nearer said actuating end.

8. A writing instrument as defined in claim 1 further comprising an arm integral with said actuating member, and wherein said actuating member is prevented from turning and said cam is mounted on said arm and is arranged to be bent both in radial and peripheral directions for producing a resilient force.

9. A Writing instrument as defined in claim 8, wherein said guide edges, with which said cam cooperates, extend parallel to the longitudinal axis of said instrument for preventing an undesirable pivoting of said arm under the action of such resilient force.

10. A writing instrument as defined in claim 9, wherein said guide edges are formed on grooves extending parallel to the axis of said casing.

11. A writing instrument as defined in claim 1, wherein said work surfaces on said upper side of said cam are inclined downwardly from their upper outer side'to their inner side, and said guide edges have an inclination behind which said work surfaces of said cam engage.

References Cited UNITED STATES PATENTS LAWRENCE CHARLES, Primary Examiner. 

